SN54ALS257A, SN54ALS258A, SN74ALS257A, SN74ALS258A, SN74AS257, SN74AS258
QUADRUPLE 2 LINE TO 1 LINE DATA SELECTORS/MULTIPLEXERS
WITH 3 STATE OUTPUTS
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
D
3-State Outputs Interface Directly With
D
D
System Bus
Provide Bus Interface From Multiple
Sources in High-Performance Systems
Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
SN54ALS257A, SN54ALS258A . . . J PACKAGE
SN74ALS257A, SN74ALS258A, SN74AS257,
SN74AS258 . . . D OR N PACKAGE
(TOP VIEW)
description
These data selectors/multiplexers are designed
to multiplex signals from 4-bit data sources to
4-output data lines in bus-organized systems. The
3-state outputs do not load the data lines when the
output-enable (OE) input is at a high logic level.
The SN54ALS257A and SN54ALS258A are
characterized for operation over the full military
temperature range of −55°C to 125°C. The
SN74ALS257A, SN74ALS258A, SN74AS257,
and SN74AS258 are characterized for operation
from 0°C to 70°C.
A/B
1A
1B
1Y
2A
2B
2Y
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
OE
4A
4B
4Y
3A
3B
3Y
SN54ALS257A, SN54ALS258A . . . FK PACKAGE
(TOP VIEW)
1B
1Y
NC
2A
2B
3
4
5
6
7
8
A/B
NC
VCC
OE
2 1 20 19
18
17
16
15
1A
14
9 10 11 12 13
4A
4B
NC
4Y
3A
NC − No internal connection
FUNCTION TABLE
INPUTS
DATA
OE
H
L
L
L
L
A /B
A
X
L
L
H
H
X
L
H
X
X
B
X
X
X
L
H
OUTPUT Y
SN54ALS257A
SN74ALS257A
SN74AS257
Z
L
H
L
H
SN54ALS258A
SN74ALS258A
SN74AS258
Z
H
L
H
L
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright
1996, Texas Instruments Incorporated
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
•
2Y
GND
NC
3Y
3B
1
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
SN54ALS257A, SN54ALS258A, SN74ALS257A, SN74ALS258A, SN74AS257, SN74AS258
QUADRUPLE 2 LINE TO 1 LINE DATA SELECTORS/MULTIPLEXERS
WITH 3 STATE OUTPUTS
logic symbols
†
SN54ALS257A, SN74ALS257A,
SN74AS257
15
OE
A /B
1A
1B
2A
2B
3A
3B
4A
4B
2
3
5
6
11
10
14
13
12
4Y
9
3Y
7
2Y
1
1
1
EN
G1
MUX
4
15
OE
A /B
1A
1Y
1B
2A
2B
3A
3B
4A
4B
2
3
5
6
11
10
14
13
12
4Y
9
3Y
7
2Y
1
1
1
SN54ALS258A, SN74ALS258A,
SN74AS258
EN
G1
MUX
4
1Y
† These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, J, and N packages.
logic diagrams (positive logic)
SN54ALS257A, SN74ALS257A,
SN74AS257
OE
A/B
15
1
OE
A /B
15
1
SN54ALS258A, SN74ALS258A,
SN74AS258
1A
1B
2A
2B
3A
3B
4A
4B
2
4
3
5
7
6
11
9
10
14
12
13
4Y
3Y
2Y
1Y
1A
1B
2A
2B
3A
3B
4A
4B
2
4
3
5
7
6
11
9
10
14
12
13
4Y
3Y
2Y
1Y
Pin numbers shown are for the D, J, and N packages.
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
•
SN54ALS257A, SN54ALS258A, SN74ALS257A, SN74ALS258A, SN74AS257, SN74AS258
QUADRUPLE 2 LINE TO 1 LINE DATA SELECTORS/MULTIPLEXERS
WITH 3 STATE OUTPUTS
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, V
I
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Voltage applied to a disabled 3-state output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Maximum power dissipation at T
A
= 55°C (in still air) (see Note 1): D package . . . . . . . . . . . . . . . . . . . 1.3 W
N package . . . . . . . . . . . . . . . . . . . 1.1 W
Operating free-air temperature range, T
A
: SN54ALS257A, SN54ALS258A . . . . . . . . . . . . . . −55°C to 125°C
SN74ALS257A, SN74ALS258A . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage temperature range, T
stg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 750 mils,
except for the N package, which has a trace length of zero.
recommended operating conditions
SN54ALS257A
SN54ALS258A
MIN
VCC
VIH
VIL
IOH
IOL
TA
Supply voltage
High-level input voltage
Low-level input voltage
High-level output current
Low-level output current
Operating free-air temperature
−55
4.5
2
0.7
−1
12
125
0
NOM
5
MAX
5.5
SN74ALS257A
SN74ALS258A
MIN
4.5
2
0.8
−2.6
24
70
NOM
5
MAX
5.5
V
V
V
mA
mA
°C
UNIT
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
•
3
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
SN54ALS257A, SN54ALS258A, SN74ALS257A, SN74ALS258A, SN74AS257, SN74AS258
QUADRUPLE 2 LINE TO 1 LINE DATA SELECTORS/MULTIPLEXERS
WITH 3 STATE OUTPUTS
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
VOH
TEST CONDITIONS
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
VCC = 4.5 V
VCC = 4.5 V
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
SN54ALS257A,
SN74ALS257A
ICC
SN54ALS258A,
SN74ALS258A
VCC = 5.5 V
VCC = 5.5 V
II = −18 mA
IOH = −0.4 mA
IOH = −1 mA
IOH = −2.6 mA
IOL = 12 mA
IOL = 24 mA
VO = 2.7 V
VO = 0.4 V
VI = 7 V
VI = 2.7 V
VI = 0.4 V
VO = 2.25 V
Outputs high
Outputs low
Outputs disabled
Outputs high
Outputs low
Outputs disabled
−20
3
8
9
2.5
7
8
SN54ALS257A
SN54ALS258A
MIN
VCC−2
2.4
TYP†
MAX
−1.5
VCC−2
3.3
2.4
0.25
0.4
20
−20
0.1
20
−0.1
−112
8
12
14
5
11
13
−30
3
8
9
2.5
7
8
3.2
0.25
0.35
0.4
0.5
20
−20
0.1
20
−0.1
−112
6
12
14
4
11
13
mA
V
µA
µA
mA
µA
mA
mA
V
SN74ALS257A
SN74ALS258A
MIN
TYP†
MAX
−1.5
V
UNIT
VOH
IOZH
IOZL
II
IIH
IIL
IO‡
† All typical values are at VCC = 5 V, TA = 25°C.
‡ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500
Ω,
R2 = 500
Ω,
TA = MIN to MAX§
SN54ALS257A
MIN
tPLH
tPHL
tPLH
tPHL
tPZH
tPZL
tPHZ
tPLZ
2
A or B
A /B
OE
OE
Any Y
Any Y
Any Y
Any Y
2
4
6
3
4
2
2
MAX
12
14
21
25
20
22
12
35
SN74ALS257A
MIN
2
2
6
6
4
5
2
4
MAX
10
12
18
22
16
18
10
15
ns
ns
ns
ns
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
UNIT
§ For conditions shown MIN or MAX, use the appropriate value specified under recommended operating conditions.
4
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
•
SN54ALS257A, SN54ALS258A, SN74ALS257A, SN74ALS258A, SN74AS257, SN74AS258
QUADRUPLE 2 LINE TO 1 LINE DATA SELECTORS/MULTIPLEXERS
WITH 3 STATE OUTPUTS
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500
Ω,
R2 = 500
Ω,
TA = MIN to MAX†
SN54ALS258A SN74ALS258A
MIN
tPLH
tPHL
tPLH
tPHL
tPZH
tPZL
tPHZ
tPLZ
1
A or B
A /B
OE
OE
Any Y
Any Y
Any Y
Any Y
2
4
5
3
5
2
3
MAX
12
9
28
25
20
21
12
37
MIN
2
2
5
6
4
5
2
4
MAX
8
7
25
20
18
18
10
18
ns
ns
ns
ns
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
UNIT
† For conditions shown MIN or MAX, use the appropriate value specified under recommended operating conditions.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
‡
Supply voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, V
I
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Voltage applied to a disabled 3-state output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Maximum power dissipation at T
A
= 55°C (in still air) (see Note 1): D package . . . . . . . . . . . . . . . . . . . 1.3 W
N package . . . . . . . . . . . . . . . . . . . 1.1 W
Operating free-air temperature range, T
A
: SN74AS257, SN74AS258 . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage temperature range, T
stg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
‡ Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 750 mils,
except for the N package, which has a trace length of zero.
recommended operating conditions
SN74AS257
SN74AS258
MIN
VCC
VIH
VIL
IOH
IOL
TA
Supply voltage
High-level input voltage
Low-level input voltage
High-level output current
Low-level output current
Operating free-air temperature
0
4.5
2
0.8
−15
48
70
NOM
5
MAX
5.5
V
V
V
mA
mA
°C
UNIT
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
•
5
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
